Project Summary Abdominal wall hernia repair is one of the most common operations performed in the United States. Despite nearly every general surgeon in the country performing hernia repair, it remains the most systematically understudied surgical procedure. Considerable variability in surgical approach exists for even the most basic hernias. This variability results in suboptimal patient outcomes, both long and short term, as well as a 3.2-billion-dollar cost to the healthcare system. The lack of comparative effectiveness research impedes evidence-based practice. There are three key knowledge gaps to be addressed. First, we do not understand the relationship between different surgical approaches, (e.g., minimally invasive and open) for hernia repair and patient outcomes. Second, it is unclear whether it is necessary to tailor surgical approach based on patient characteristics. Finally, the barriers and enablers to adoption of evidence-based practice across hernia surgeons have not been explored. This proposal will address these key gaps. Leveraging the capital from two unique data registries, the America Hernia Society Quality Collaborative (AHSQC) and the Michigan Surgery Quality Collaborative (MSQC), we will explore the effectiveness of commonly employed surgical approaches by hernia type and patient characteristics. Synthesizing this data with relevant comparative effectiveness literature, we will develop evidence-based hernia recommendations and qualitatively assess the barriers and facilitators to surgeon implementation of the proposed recommendations. The aims of this research proposal are to 1) Evaluate the comparative effectiveness of commonly performed surgical techniques for hernia repair 2) Identify heterogeneity in comparative effectiveness of hernia repair by patient subgroups 3) Identify the barriers and facilitators to implementation of evidence-based hernia practice, based on hernia and patient characteristics. In addition to the innovative research plan, this proposal will provide the career development candidate (Dana Telem) with a rich mentorship experience. It will also provide her with the methodologic training in comparative effectiveness research and a strong theoretical background in implementation science. This project will lay the groundwork for Dr. Telem to become an independent investigator focused on developing and implementing evidence-based approaches for common surgical problems.